WASHINGTON -- A Democratic Super PAC is out with the first negative TV advertisement against Republican Senate candidate Bill Cassidy.

The ad by the Senate Majority PAC hits Cassidy, a doctor and a Republican congressman from Baton Rouge, for voting to raise the retirement age to 70, and alludes to a provision in a Republican Study Committee budget proposal he supported. It also hits him for "voting 16 times" to shut the government down.

"That's Congressman Cassidy's record in the House," the ad's narrator says. "He'd hurt us even more in the Senate."

As a super political action committee, the Senate Majority PAC can raise unlimited contributions. It works on behalf of Democratic Senate candidates such as Sen. Mary Landrieu, D-La.

The 16 votes referenced in the ad relates to the bills GOP members brought up during the 16-day government shutdown in October, including measures to reopen some services and agencies piecemeal. Among them: national parks, food stamps, medical research and veterans benefits.

The bills went nowhere because the Senate Democrats maintained the position throughout the impasse that they would support only a comprehensive bill to reopen the entire federal government.

The Rothenberg Political Report suggests that the ads may offer a sneak peek of how Democrats and pro-Democratic political organizations hope to tie Republican House candidates -- and House members, like Cassidy, who are running for the Senate -- to the partial government shutdown in October.

Democrats had Republicans on the defensive about the partial government shutdown in October, but lately the GOP has been using the rough rollout of the Affordable Care Act as a major attack point against Democrats, like Landrieu, who voted for the health care law in 2010.

They have been hammering away at the president's promise in 2010 -- repeated by many Democrats, including Landrieu -- that people could keep their insurance if they were satisfied with the coverage, a pledge that proved untrue when companies began canceling policies that didn't meet minimal benefits standards of the Affordable Care Act.

Since then, the president has asked state insurance commissioners to allow people to keep their previous policies. Louisiana Insurance Commissioner Jim Donelon responded affirmatively to the president's request, and is allowing state insurance companies to inform policyholders that they can renew their coverage -- even if cancellation letters had already been mailed out.

Some lawmakers, including Landrieu, have introduced legislation to allow people to keep their policies -- as long as their insurers provided information that policyholders might want more comprehensive coverage at affordable rates on the health care law's exchanges.

"It's no coincidence that just last week President Obama and Mary Landrieu won PolitiFact's lie of the year -- falsely claiming that, 'If you like your health care, you can keep it," Joel DiGrado, Cassidy's campaign manager, said in response to the Senate Majority PAC's anti-Cassidy ad.

Two conservative Super PACs, Americans for Prosperity and the Judicial Crisis Network, both of which get significant funding from the billionaire brothers Charles and David Koch, have been running anti-Landrieu ads for weeks.

Craig Varoga of the Senate Majority PAC said the group's 30-second ad is intended to hold Cassidy accountable.

"Congressman Cassidy is desperately trying to run from his record in Congress because he knows he is part of the problem in Washington," Varoga said.

The Sunlight Foundation lists the top donors to the Senate Majority PAC as the Massachusetts Teachers Association, $500,000; and $250,000 each from George Marcus of the Millichap Co. of Palo Alto, Calif., Priorities USA Action of Washington, D.C., and Working for Working Americans of Las Vegas,